Production of direct azo dyestuffs



Patented June 12, 1928. i

UNITED STATES PATENT OFFICE,

\ IPIO CACCIA, F NEWARK, NEW JERSEY.

PRODUCTION OF DIRECT AZO DYESTUZEFS.

No Drawing. Application filed July 20, 1926. Serial No. 123,807.

The object of my invention is the producrect colors are very good to.washing, and tion of direct colors, which can dye cotton the fastness tolight increases with the treatand artificial silk only in unions,v(mixed in ment of sodium cyanide. The colors are textiles), while thesilk will remain white. very soluble in water. 30

The artificial silk and cotton will be dyed In my Patent No. 1,609,793,issued Dewhen in a bath with soap and sodium carcen ber 17, 1926, I gavea probable formula bonate or in a bath with Glaubers salt, of the bluedisazo dyestuif, but instead of (Na SO benzidine, if, for an example Iput tolidine It is known that the introduction of suband for theamino-compound I put 2-amino- 35 stituents into amino-groups in azo dyecon1-- S-naphthol-G-sulphonic acid with the sodiponents is generallyaccomplished by imum cyanide treatment,l[Will have: proved fastnessproperties; not only that, but the shade will change too as well as theN coloring power, which will be increased. 7 i

In carrying out my invention 1 boil the on CH3 CH3 on amino-compoundwith a solution of sodium l cyamde and while warm I add sodium chlo-NHCN N HN ride and sodlum carbonate, or sodium acetate. l pour into themixture a diazotized H 3 SOzH 20 base as for example diazotizedbenzidine tolidine, or dianisidiga The Smell of In this case theproportion used is 1 mole of drocyanic acid disappears and the crystalstolidine m -2 of p of the dyestufl are immediately formed. 6S111Ph 0n1cacld- After filtration the color is dried. 1 01311113 a 25 Theroportions used are molecular, de- 1. A new series OfJLZO dyestuflshaving pending on the formula of the dye. lhe diprobably the followinggeneral formula:

no on NHON NOHN I H038 i som wherein R stands for H, CH OICHSU. 3. Theprocess of preparing a dyestufi', 2. As a new dyest-ufi, the compound ofthe which consists of coupling tetrazotized tolifollowing formula a dinewith 2-anrino-8-naphthol-6-sulfonic acid 95 QQ in the presence of sodiumcyanide. 011 ii Ha H3 on 7 P10 C N'HON NOHN non

